For both of them? Yes, a 10g is too small. *Maybe* one could go in there by himself but that would be cramped. Gouramis are pretty territorial themselves so two of them in close quarters like that would result in a lot of fighting.
I agree, though: your cichlids are small now, but both of those fish will get very aggressive as they mature and will likely kill the gouramis.
Tiger barbs: with your cichlids, they will very likely get eaten when the cichlids are large enough. With the gouramis, I would say it could be problematic but might be ok provided you have a big enough group of the barbs.